Breathing can measurably modulate neural responses in the brain

Summary: The study reveals a possible link between breathing and changes in neuronal activity in animal models.

The source: state of pennsylvania

Mental health practitioners and meditation gurus have long credited intentional breathing with the ability to bring inner calm, but scientists don’t fully understand how the brain is involved in this process.

Using functional magnetic resonance imaging (fMRI) and electrophysiology, researchers at Penn State College of Engineering have identified a possible link between breathing and changes in neuronal activity in mice.

Their results were published online before being published in eLife. The researchers simultaneously used multimodal techniques to eliminate noises typically associated with brain imaging and to localize the breathing that regulates neural activity.

said Nanyin Zhang, founding director of the Penn State Center for Neurotechnology in Mental Health Research and professor of biomedical engineering.

Imaging researchers viewed breathing as a non-neurological physiological action, such as a heartbeat or bodily movement, in fMRI. Our article advances the idea that breathing has a neural component: it affects the fMRI signal by modulating neural activity. »

By scanning the brain waves of resting rodents under anesthesia using fMRI, the researchers highlighted a network of brain regions involved in respiration.

“Breathing is a common need for almost all living animals,” Zhang said. We know that breathing is controlled by a region of the brainstem. But we didn’t have a full picture of how other areas of the brain were affected by breathing. »

Along with functional magnetic resonance imaging, the researchers used neuroelectrophysiology, which measures electrical and signaling properties in the nervous system, to link respiration to neural activity in the cingulate cortex – a region of the brain centrally of the cerebral hemisphere associated with emotional response and regulation.

Simultaneous use of fMRI and electrophysiology allowed researchers to obtain changes in non-neuronal fMRI signals relevant to data collection, such as movement and carbon dioxide exhalation.

The findings provide insight into how neural activity and fMRI signals relate to rest, Zhang said, which could inform future imaging research to understand how neurovascular signals change at rest.

“When the animals breathed, we measured how much their brain activity fluctuated with their breathing rate,” Zhang said. “When this approach is extended to humans, it could provide automated insights into how to control breathing common to meditation practices that can help reduce stress and anxiety. »

The association between neural activity in the cingulate cortex and respiratory rate may indicate that respiratory rhythms can influence emotional state, according to Chang.

“When we are anxious, our breathing often quickens,” Zhang said. “In response, we sometimes take deep breaths. Or when we focus, we tend to hold our breath. These are signs that breathing may be affecting brain function. Breathing allows us to control our emotions, for example, when we need to change the functioning of the brain. Our findings support this idea.

According to Chang, future studies could focus on observing the brain in humans as they meditate to analyze the direct relationship between slow, deliberate breathing and neural activity.

“Our understanding of what’s going on in the brain is still superficial,” Zhang said. “If researchers replicate the study in humans using the same techniques, they may be able to explain how meditation modulates neural activity in the brain. »

About this research in Neuroscience News

author: Maria Chubrinsky
The source: state of pennsylvania
Contact: Maria Chubrinsky – Pennsylvania
image: Image is in public domain

original research: free access.
” The neural scaffold of the fMRI network associated with respirationWritten by Wenyu Tu et al. eLife

Summary

The neural scaffold of the fMRI network associated with respiration

Breathing can lead to movement and carbon dioxide₂ Fluctuations during resting-state functional magnetic resonance (rsfMRI) scans, which would lead to non-neurological effects in the rsfMRI signal. Meanwhile, as a critical physiological process, respiration can directly alter neural activity in the brain and thereby modulate rsfMRI signaling.

However, this potential neural component in the relationship between respiration and fMRI is largely unexplored. To illustrate this issue, here we simultaneously recorded electrophysiological, rsfMRI, and respiratory signals in mice.

Our data show that breathing is indeed correlated with changes in neural activity, as evidenced by the phase-locking relationship between differences in slow breathing and the gamma band strength of the electrophysiological signal recorded in the anterior cingulate cortex. .

Interestingly, the differences in slow breathing are also related to the distinct rsfMRI network, which is mediated by gamma-band neural activity. Moreover, the brain network associated with respiration disappears when neural activity in the brain is silenced in an isoelectric state, while respiration is preserved, confirming the necessary role of neural activity in this network.

Taken together, this study identifies a respiration-related brain network supported by neural activity, which represents a novel component in the relationship between respiration and fMRI that differs from respiration-associated artifacts in fMRI. This opens up a new avenue for studying the interactions between respiration, neural activity, and resting-state brain networks in healthy and diseased conditions.